1. Field of the Invention
The present invention relates to a mounting head apparatus for adsorbing and moving a sheet member to a position above a required object and placing the sheet on the object and a mounting method.
2. Description of the Related Art
In general, a so-called mounting head apparatus is employed to coat an object with a sheet member after the sheet has been registered to a predetermined position. The mounting head apparatus is employed, for example, when an adhesive sheet composed of an adhesive layer and a separable film is mounted on a portion for establishing the connection between a liquid crystal panel and a TAB. When an anisotropic and conductive adhesive sheet is mounted on a predetermined position of a flexible printed substrate, also a mounting head apparatus of the foregoing type is employed.
As shown in FIG. 1, the mounting head apparatus incorporates a head 101 for adsorbing a sheet member 100, a moving means (not shown) for moving the head 101 and a vacuum pump 102 for generating adsorbing force for the head 101. The head 101 has a plurality of adsorbing openings (not shown) formed in parallel with one another in one direction. Therefore, suction force is generated in the plural adsorbing openings owning to the operation of the vacuum pump 102 so that adsorption of the sheet member 100 is permitted.
In a state of the mounting head apparatus in which the sheet member 100 has been adsorbed by the head 101, the moving means moves the head 101 to a position above an object 103 on which the sheet member 100 must be mounted. The mounting head apparatus is structured such that the head 101 holding the sheet member 100 adsorbed thereto is brought into contact with the object 103. Then, generation of the adsorbing force is interrupted so that the sheet member 100 is mounted on the object 103.
For example, an anisotropic and conductive adhesive sheet is allowed to adhere to a predetermined position of a flexible printed substrate as follows: the anisotropic and conductive adhesive sheet (hereinafter called an xe2x80x9cACFxe2x80x9d) formed into a predetermined shape is allowed to adhere to the flexible printed substrate (hereinafter called a xe2x80x9cFPCxe2x80x9d) by the foregoing mounting head apparatus (temporal adhesion). Then, a heating head or the like is operated to allow the ACF and the FPC to completely adhere to each other (main adhesion).
The mounting head apparatus structured as described above enables the predetermined sheet member 100 to easily be mounted on a required position of the object 103. Therefore, the operation for mounting the sheet member 100 has substantially been automated.
At present, reduction of sizes of electronic apparatuses incorporating FPC and so forth has caused the sizes of the FPC and so forth to be reduced. Hence it follows that also the foregoing sheet member, such as the ACF, must considerably accurately be mounted on an object on which the sheet member must be mounted and which has reduced size.
The foregoing mounting head apparatus has the structure that the suction force is generated in the plural adsorbing openings formed in one direction. Therefore, the sheet member 100 must have the size with which all of the plural adsorbing openings can be covered to realize sufficiently large force for adsorbing the sheet member 100. That is, a portion of the adsorbing openings which does not adsorb the sheet member 100 deteriorates the effect of the negative pressure. Therefore, the force for adsorbing the sheet member 100 becomes insufficient.
To prevent the foregoing problem, a method may be employed with which change to a head 101 corresponding to a small sheet member 100 is performed. Another method may be employed with which a portion of the adsorbing openings is masked to correspond to the small sheet member 100. The operation for changing the head 101 and that for performing masking are very complicated operations, causing the productivity to excessively deteriorate. Although each of the foregoing methods is able to generate the adsorbing force corresponding to the small sheet member 100, there arises a problem in that the force for adsorbing a large sheet member 100 is insufficiently small when the large and small sheet members 100 are alternately mounted.
To prevent the problems experienced with the conventional mounting head apparatus and the mounting method, an object of the present invention is to provide a mounting head apparatus and a mounting method each of which is capable of satisfactorily adsorbing any one of sheet members regardless of the size of the sheet member and accurately mounting the sheet member on a required position on an object.
To achieve the above-mentioned object, according to one aspect of the present invention, there is provided a mounting head apparatus for adsorbing and moving a sheet member to a position above an object on which the sheet member must be mounted and mounting the adsorbed sheet member on the object, the mounting head apparatus comprising an adsorbing portion having a plurality of adsorbing openings formed at the leading end thereof; a connection chamber to which the adsorbing portion is joined and which is formed into a space for connecting the base portions of the plural adsorbing openings to one another; dividing means disposed in the connection chamber and arranged to divide the internal space of the connection chamber into a plurality of sections; and pressure reducing means connected to the connection chamber and arranged to reduce the pressure in the connection chamber, wherein adsorbing force is generated from a portion of the plural adsorbing openings in a predetermined region when the dividing means divides the inside portion of the connection chamber at a predetermined position and the pressure in at least either of the divided connection chambers is reduced by the pressure reducing means.
The mounting head apparatus according to the present invention and structured as described above incorporates the dividing means which is capable of dividing the connection chamber at a required position. The mounting head apparatus reduces the pressure in at least either of the divided connection chambers to generate adsorbing force. At this time, the dividing means of the mounting head apparatus determines the dividing position in the connection chamber according to the size of the sheet member which must be adsorbed. As a result, the mounting head apparatus according to the present invention is able to generate the adsorbing force from the adsorbing openings formed in a predetermined region according to the size of the sheet member. Thus, the mounting head apparatus is able to adsorb a sheet member having a predetermined size.
To achieve the foregoing object, according to another aspect of the present invention, there is provided a mounting method arranged to adsorb and move a sheet member to a position above an object on which the sheet member must be mounted and mount the adsorbed sheet member on the object, the mounting head method comprising the steps of: using a mounting head apparatus incorporating an adsorbing portion having a plurality of adsorbing openings formed at the leading end thereof, a connection chamber to which the adsorbing portion is joined and which is formed into a space for connecting the base portions of the plural adsorbing openings to one another, dividing means disposed in the connection chamber and arranged to divide the internal space of the connection chamber into a plurality of sections, and pressure reducing means connected to the connection chamber and arranged to reduce the pressure in the connection chamber; causing the dividing means to divide the inside portion of the connection chamber at a predetermined position; and causing the pressure reducing means to reduce the pressure in at least either of the divided connection chambers so that adsorbing force is generated from a portion of the plural adsorbing openings in a predetermined region, and the adsorbing force is used to adsorb the sheet member.
The mounting method according to the present invention and structured as described above causes the dividing means to divide the connection chamber at a required position. Moreover, the pressure in at least either of the divided connection chambers is reduced to generate adsorbing force in predetermined adsorbing openings to adsorb the sheet member. Therefore, the method according to the present invention arranged to adjust the dividing means to control the position at which the connection chamber is divided is able to generate adsorbing force from a portion of the plural adsorbing openings in required region. Thus, the foregoing method enables the region in which the adsorbing force is generated to be adjusted according to the size of the sheet member so that the sheet member is adsorbed.